"Oragenics' approach to stopping tooth decay is straightforward: they have used recombinant DNA technology to produce a new variety of S. mutans which does not excrete lactic acid. Instead, it excretes tiny amounts of an agent called Mutacin 1140 which is deadly to other strains of S. mutans, giving these new bacteria an edge over the existing organisms. Once the modified bacteria get a toehold in the mouth, the existing population of S. mutans will be methodically wiped out, leaving the non-acid-producing bacteria in its place. In the absence of acid-producing bacteria, the teeth have little to fear."
Sign me up for the mutant bacteria! Seriously, sign me up -- I hate flossing. Actually sign my kids up too -- dental bills are such a downer.